Method of treating vegetable fibrous material and resulting product



Pat nted, July 12, 1932 TUNITED STAT-ES PATENT OFFICE oneness imrnnnnm mmnarnonmna, or wa'r'rwm swn'znnmn METHOD OF TREATING VEGETABLE FIBROUSMATERIAL ANDBESULTTNG PRODUCT lI'o Drawing. Application filed Rovember23, 1928, Serial No. 821,508, and in Germany November 28, 1927.

This invention-relates to method of treating vegetable fibrous materialand resulting product, and more particularly to subjectmg such materialto a. plurality of acid treat- 5 ments to produce swelling actions forthe productionof permanent finish efiects.

- The object "of the invention is to produce improved permanent finisheffects in celluloslc or vegetable fibrous material by swelling actions.

7 Further objects and advantages of the invention willmore fully appearfrom the followin description wherein a preferred manner o carrying outthe invention to produce a linen effect is'set forth byway of example;but the invention will be more particularly pointed out in the appendedclaims.

It is already a well known practice to treat vegetable fibrous materialswith various mineral acids such for example as nitric, sulphuric andhydrochloric acids, for the purpose of attaining by swelling actions,various permanent finish effects, for example transparent effects, lineneffects and other efi'ects. Even a plurality of treatments with acidhave been used, combined if necessary with a treatment with causticalkali.

In all these well known processes the procedure has hitherto been,without exception, that in each instance after a swelling reaction hastaken place by one acid treatment the swelling was interrupted beforethe next' acid treatment was commenced. Theinterposed washing process inevery instance resulted in bringing about a .coagulation'of the materialthat was subjected to the swelling action. 4 Now, it has been found thatvarious novel,

in case of a twofold: or multiple swellingwith acids, this coagulationbetween two swelling operations is obviated, i. e., if the swellingaction by the second acid treatment is a direct continuation of thefirst'without interruption, so that one swelling stage merges directlyinto another. These novel effects may be attained by means of variousconcentrated mineral acids under suitable conditions, by means ofalternating their swelling action upon cotton without anyintermedltechnically valuable effects are produced if,

ate coagulation. Between the acid treatments the excess of the firstacid is removed first acid must be effected as exhaustively as possible,but on the other hand only to such an extent that the state of swellingis not interrupted thereby. i

The applicability of the process comprises all possible ve etablefibrous materials in any form. Thus, For example, cotton may be improvedeither raw, bleached, or merc'erized, as a fabric or loose. The'e-fiects that are obtained are different accordin to the type of thefabric and of the swelling agents employed. In this way wool-like andsoft, stiff and transparent, and also linen-like qualities ma beobtained with'or without a lustrouse ect. By means of suitable handling,as will be' understood by those skilled in the art in the light of thisdisclosure. it isalso possible to proceedin such manner-that in theaction of the swelling agents the fabric is not changed through andthrough, but that the swelling takes place only-on one side andsuperficially. With this invention there is always produced an increasedeffect-of 'the' swelling in com arison'with that 'due to an individualswelling-action by one of the acids used, or to the same number ofswelling ac-. tions where an intermediate coagulation 1s permittedbetween such acid actions.

' Example of ewewtz'on Whereas the two agents applied by themselves areca able ofefiecting merely a densification of t e fabric, there isproduced by reviously treated cotton muslin is l d loosely intosulphuric acid of 50 the new process a stifi' semi-transparent effect ofa peculiar character with considerable contraction of the fabric.

While we have described the invention in detail with respect to oneembodiment thereof, it will be understood by those skilled in the art,after understanding the invention,'.

that various changes and modifications may be made Witho departing fromthe spirit or scope of the i vention, and in the appendedclaims we aimto cover all such changes and modifications.

Having thus described our invention, what We claim as new and desire tosecure by Letters Patent, is:

'1. Method of producing permanent finish eflects on cellulosic material.which comprises subjecting the material to a plurality of swell ingactions, each by concentrated mineral acid under swelling conditions,and without permitting an intermediate coagulation of the materialbetween such actions.

2. Method of producing permanent finish effects on cellulosic fabric,which comprises subjectingthe fabric to a swelling action by aconcentrated mineral acid, removing the excess acid from the materialand again subjecting the material to a swelling action by a concentratedmineral acid without permitting an intermediate coagulation of thematerial between such actions.

3. Method of producin permanent finish effects on cotton fabric, w ichcomprises subjecting the material to a plurality of swelling actionseach by a different concentrated mineral acid, and without permitting anintermediate coagulation of the material between such actions, andbefore the second of said actions removing the excess acid from saidmaterial.

4. The method of producing permanent I finished effects on cellulo'sicmaterial which comprises subjecting the-material to'a plurality ofswelling actions, each by concentrated .mineral acid under swellingconditions, the

acid employed in one treatment differingfrom the acid employed in thesucceeding treatment and without permitting an intermediate coagulationof the material between such act-ions.

In testimony whereof we have signed our names to this ecification.

( iSIORGES 'HEBERLEIN. ALBERT BODMER.

